Internet naming board Icann has approved a vast expansion of domain suffixes to the existing 22 international ones such as .com as well as allowing scripts other than the Roman alphabet. Photograph: Armando Franca/AP

Twenty-six years after .com was first unveiled to the world, officials have swept away tight regulations governing website naming, opening up a whole world of personalised web address suffixes.

Icann, the internet naming board, approved one of the biggest changes in the web's history on Monday, allowing the number of web suffixes to expand virtually without limit. Currently there are 22 international "top level domain" suffixes such as ".com", but sites with suffixes such as ".sport" and ".eco" will pop up next year.

Peter Dengate Thrush, chairman of Icann's board of directors, said: "Today's decision will usher in a new internet age. We have provided a platform for the next generation of creativity and inspiration. Unless there is a good reason to restrain it, innovation should be allowed to run free."

Analysts say they expect 500 to 1,000 domain suffixes, mostly for companies and products looking to stamp their mark on web addresses, but also for cities and generic names such as .bank or .hotel.

Websites can now be categorised by subjects such as industry, geography and ethnicity – as well as using Arabic, Chinese and other scripts. There are also 290 country suffixes such as ".uk" and ".fr", which will remain unchanged for now.

Groups have formed to back ".sport" for sporting sites, and two conservationist groups separately are seeking the right to operate an ".eco" suffix.

It will also now be possible to have website names entirely in Mandarin or Cyrillic or any other script, which will ease the problem of reading and writing addresses for the majority of people who do not use the Roman alphabet.

The growth will also come as the internet shifts to the next-generation IPv6 addressing system for its basic systems, which enables far more devices to be attached to the internet.

Icann approved the move after six years of negotiations, in which concerns were repeatedly expressed that the enormous expansion of suffixes could lead to extra costs for businesses of registering a site with their trademark as the number of suffixes explodes.

During the 1990s there were hundreds of cases of "domain squatting" in which people would register sites that used companies' trademarked names, effectively holding them to ransom. Expanding the number of domains could make that far worse.

But it would also ease the pressure on the ".com" domain, created 26 years ago. In May 2009 a study found that 74% of websites were in the .com domain space.

"It will allow corporations to better take control of their brands," said Theo Hnarakis, chief executive of Melbourne IT, which manages online brands for clients such as Volvo, LEGO and GlaxoSmithKline. "For example, .apple or .ipad would take customers right to those products."

But others said that the promise of space could be a double-edged sword. "If you're a company with a lot of money, such as Barclays, then you could buy the '.barclays' suffix and build a little island on the internet, on the basis that you can persuade customers that only legitimate Barclays sites will end with that," said Charlie Abrahams, of the brand protection company MarkMonitor. "If your brand has just three letters, it might be worth it. If you're Tommy Hilfiger, it's probably not, because I can't imagine anyone bothering to type all that at the end of a URL."

However, the principal beneficiaries are likely to be the internet registrars who sell the rights to site names. Icann has set a $185,000 fee per suffix, and applicants have to work their way through a 360-page guidebook to prepare their bids ahead of the first suffix auctions, which start on 12 January 2012 and run for 90 days.

Icann says it will auction suffixes if multiple parties have legitimate claims. However, it expects companies will reach deals to avoid a public auction.

"I think we'll see much more of that going on than see auctions generating circuses," said Dengate Thrush. "But there is that prospect that there will be a couple of identical applicants and applications."

Adrian Kinderis, chief executive of AusRegistry International, which helps companies to register domains and manages names such as ".au" for Australia, said: "It's a significant undertaking. We're calling it the Olympic bid. But it's worth it for corporations that have suffered from things like trademark infringement and can now carve out a niche on the internet."

Abrahams estimates that it would cost a typical company £1m to run their own suffix for the minimum 10 years required. "It is a lot of work – but if someone beats you to it, you have lost it forever," he noted.

The Icann board approved the move by 13 votes to one with two abstentions in a meeting in Singapore. "This is the start of a whole new phase for the Internet," said But tThe move could also create enormous confusion for consumers and companies. It greatly expands the risks from "phishing" sites because they could use confusing domain names in language scripts that look similar to existing ones to capture peoples' details. And for companies, the challenge will be to decide whether to register their names in all possible domains, or to create their own suffix, or to limit themselves to a small number of domains.